The Night Sky, Mythology, and Timescales

Many of you have likely seen the image that shows what the night sky would look like if the Andromeda galaxy were far brighter, making it clear that in its entirety it appears as several times bigger than the moon. The Reddit threadabout it though is incredibly fascinating, discussing everything from the accuracy of the image (it seems to be correct) to when the Andromeda galaxy will collide with our own.

But the most fascinating part of the thread discusses the impact this change to the night sky would have on our mythology and how we think of ourselves:

If it actually looked like this, imagine the sorts of mythology ancient humans would have created about it. I mean, look at all the sun and moon gods we have...imagine if our night sky looked like THAT!

This in turn led to a number of commenters highlighting the fact that the Milky Way, outside of light pollution, is extremely visible and has had a large impact on our mythology.

But there was one point when it took a fascinating turn: into science fiction. The classic Isaac Asimov story Nightfall was mentioned, which is premised on the question of what would happen to the inhabitants of a planet that is part of a multi-star system, where true nightfall (with its attendant starry sky) would only occur once every thousand years. Asimov's answer: total civilizational madness and collapse. This story seems to have been a response to a quote from Ralph Waldo Emerson:

If the stars should appear one night in a thousand years, how would men believe and adore, and preserve for many generations the remembrance of the city of God!

So how much does the timescale of phenomena in the sky matter? Permanent fixtures are gods (sun, moon, planets), but what about supernovas or eclipses? Or extremely rare nightfall? How do we respond to these? Well, when it comes to eclipses, there is quite the collection of stories. But they all seem to boil down to a single theme:

"If you do a worldwide survey of eclipse lore, the theme that constantly appears, with few exceptions, is it's always a disruption of the established order," said E. C. Krupp, director of the Griffith Observatory in Los Angeles, California. That's true of both solar and lunar eclipses.

So for transient and unexpected events, we might expect "a disruption of the established order." But what happens if something unexpected happens for a longer period of time? I can't think of any such real-world equivalents, so the closest analogue is again from science fiction (and also mentioned in the thread), specifically an episode of Star Trek: Voyagerwhere a starship appears in the sky and lasts for a thousand years in the skies (watch it online here). It affects culture in countless ways, from their myths to their eventual scientific progress.

Sunrises and the phases of the moon are all regular enough changes to become part of mythology but also part of the established order. No doubt a very bright Andromeda galaxy would achieve a similar place, unless it suddenly appeared. And then, it seems, we would definitely get some weird myths.

Top image:Phil Plait/Flickr/CC